My husband tells me I can hurt my wrist by my hobby, which I'm turning into a business: cake decorating. Is he right?
Cake decorating, if you use a bag to squeeze the icing, can cause a repetitive stress injury. The motion of squeezing the bag and moving your hand back and forth, especially for repeating designs, could cause irritation in the carpal tunnel area - on the nerve that passes through. This would cause pain or numbness (or both) in your hand.
If you start waking up with a feeling that your hand has gone to sleep or you are woken up with pain in your wrist, you should get it checked. Problems like carpal tunnel syndrome can be caused by hobbies too.